The leaked memo had said that officials had set “a target of achieving 12,800 enforced returns in 2017-18.” The leaked memo also boasts that “we have exceeded our target of assisted returns' and that progress had been made on achieving the 10 per cent increase in deportations they had promised Ms Rudd.”

The memo, leaked to The Guardian, contradicted evidence the secretary gave to the Home Affairs select committee just three days ago when she said she was not aware of any targets.

Rudd’s claims also contradicted evidence given to the same committee by representatives of immigration staff, who insisted employees are given targets for how many people they should deport.

The Windrush scandal

For nearly two weeks, British ministers have been struggling to explain why some descendants of the "Windrush generation", who were invited to Britain to plug labor shortfalls between 1948 and 1971, had been labeled illegal immigrants.

Much like Dreamers who were brought to the United States as children, many immigrant kids who arrived in the United Kingdom from the Caribbean and other former British colonies a half-century ago face an uncertain future.

They are the descendants a generation, named after a ship — the MV Empire Windrush — that docked in the UK in June 1948 with cleaners, bus drivers, bricklayers and nurses from Jamaica, Trinidad and Tobago and other British territories as labor who would reconstruct war-ravaged Britain.

They arrived in the UK legally under previous freedom of movement laws for nationals of the Commonwealth, an intergovernmental organization of 53 member states that were mostly former territories of the British Empire. The immigrants did not need elaborate documentation or proof of British citizenship. Many never registered and did not obtain papers or documents of citizenship.

Changes to migration rules mean those who lack documents are now being told they need evidence to continue working, access key services or even remain in the UK

The new rules on immigration mean some of these immigrants are now being classified as illegal. They have faced deportation threats and in some cases stripped of their rights to access health care, employment and pensions.

The issue has come to light following a new round of clampdowns on illegal immigration in recent years, with requirements for people to have documentation to work, rent a property or access benefits including healthcare.

Rudd on Wednesday had told lawmakers that Britain did not have targets for removals of immigrants.